<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/tools/perf/util/tool.h, branch v4.9</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>perf tools: Add time conversion event</title>
<updated>2016-03-31T13:52:24+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2016-03-08T08:38:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=46bc29b970f0011a9099077f1db8f3540aa829fe'/>
<id>46bc29b970f0011a9099077f1db8f3540aa829fe</id>
<content type='text'>
Intel PT uses the time members from the perf_event_mmap_page to convert
between TSC and perf time.

Due to a lack of foresight when Intel PT was implemented, those time
members were recorded in the (implementation dependent) AUXTRACE_INFO
event, the structure of which is generally inaccessible outside of the
Intel PT decoder.  However now the conversion between TSC and perf time
is needed when processing a jitdump file when Intel PT has been used for
tracing.

So add a user event to record the time members.  'perf record' will
synthesize the event if the information is available.  And session
processing will put a copy of the event on the session so that tools
like 'perf inject' can easily access it.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1457426324-30158-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Intel PT uses the time members from the perf_event_mmap_page to convert
between TSC and perf time.

Due to a lack of foresight when Intel PT was implemented, those time
members were recorded in the (implementation dependent) AUXTRACE_INFO
event, the structure of which is generally inaccessible outside of the
Intel PT decoder.  However now the conversion between TSC and perf time
is needed when processing a jitdump file when Intel PT has been used for
tracing.

So add a user event to record the time members.  'perf record' will
synthesize the event if the information is available.  And session
processing will put a copy of the event on the session so that tools
like 'perf inject' can easily access it.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1457426324-30158-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add event_update user level event</title>
<updated>2015-12-17T18:10:16+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2015-10-25T14:51:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ffe777254cce24fb5fde3f0aa91fc755cfb1b812'/>
<id>ffe777254cce24fb5fde3f0aa91fc755cfb1b812</id>
<content type='text'>
It'll serve as a base event for additional event attributes details,
that are not part of the attr event.

At the moment this event is just a dummy one without any specific
functionality. The type value will distinguish the update event details.
It'll come in the following patches.

The idea for this event is to be extensible for any update that the
event might need in the future.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-21-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It'll serve as a base event for additional event attributes details,
that are not part of the attr event.

At the moment this event is just a dummy one without any specific
functionality. The type value will distinguish the update event details.
It'll come in the following patches.

The idea for this event is to be extensible for any update that the
event might need in the future.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-21-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add stat round user level event</title>
<updated>2015-12-17T17:55:43+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2015-10-25T14:51:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2d8f0f18a5c37cf0322cb385b99adb1167b7cf78'/>
<id>2d8f0f18a5c37cf0322cb385b99adb1167b7cf78</id>
<content type='text'>
Adding the stat round event to be stored after each stat interval round,
so that report tools (report/script) gets notified and process interval
data.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-18-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding the stat round event to be stored after each stat interval round,
so that report tools (report/script) gets notified and process interval
data.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-18-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add stat user level event</title>
<updated>2015-12-17T17:38:20+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2015-10-25T14:51:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d80518c90bb2b4af9755d79af5dfe9d44e04cdb9'/>
<id>d80518c90bb2b4af9755d79af5dfe9d44e04cdb9</id>
<content type='text'>
Adding a stat event to store a 'struct perf_counter_values' for a given
event/cpu/thread.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-15-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding a stat event to store a 'struct perf_counter_values' for a given
event/cpu/thread.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-15-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add stat config user level event</title>
<updated>2015-12-17T17:38:18+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2015-10-25T14:51:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=374fb9e362f64e730388abc1de9bb93829670a54'/>
<id>374fb9e362f64e730388abc1de9bb93829670a54</id>
<content type='text'>
Adding the stat config event to pass/store stat config data, so report
tools (report/script) know how to interpret stat data.

The config data is stored in a 'tag|value' way to allow for easy
extension and backwards compatibility.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-12-git-send-email-jolsa@kernel.org
[ stat_config_term_event -&gt; stat_config_event_entry ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding the stat config event to pass/store stat config data, so report
tools (report/script) know how to interpret stat data.

The config data is stored in a 'tag|value' way to allow for easy
extension and backwards compatibility.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-12-git-send-email-jolsa@kernel.org
[ stat_config_term_event -&gt; stat_config_event_entry ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf cpu_map: Add cpu_map user level event</title>
<updated>2015-12-17T17:38:17+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2015-10-25T14:51:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6640b6c227fc85fd8bdcc4a31239a04450487f6a'/>
<id>6640b6c227fc85fd8bdcc4a31239a04450487f6a</id>
<content type='text'>
Adding the cpu_map event to pass/store cpu maps as data in
a pipe/perf.data.

We store maps in 2 formats:
  - list of cpus
  - mask of cpus

The format that takes less space is selected transparently in the
following patch.

The interface is made generic, so we could add the cpumap event data
into another event in the following patches.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-8-git-send-email-jolsa@kernel.org
[ cpu_map_data_cpus -&gt; cpu_map_entries, cpu_map_data_mask -&gt; cpu_map_mask ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding the cpu_map event to pass/store cpu maps as data in
a pipe/perf.data.

We store maps in 2 formats:
  - list of cpus
  - mask of cpus

The format that takes less space is selected transparently in the
following patch.

The interface is made generic, so we could add the cpumap event data
into another event in the following patches.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-8-git-send-email-jolsa@kernel.org
[ cpu_map_data_cpus -&gt; cpu_map_entries, cpu_map_data_mask -&gt; cpu_map_mask ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf thread_map: Add thread_map user level event</title>
<updated>2015-12-17T17:38:16+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2015-10-25T14:51:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5f3339d2e83ca587c2e13c3e37e1b5fb7c68ebe5'/>
<id>5f3339d2e83ca587c2e13c3e37e1b5fb7c68ebe5</id>
<content type='text'>
Adding the thread_map event to pass/store thread maps as data in
the pipe/perf.data.

Storing the thread ID along with the standard comm[16] thread name string.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-4-git-send-email-jolsa@kernel.org
[ Renamed thread_map_data_event to thread_map_event_entry ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adding the thread_map event to pass/store thread maps as data in
the pipe/perf.data.

Storing the thread ID along with the standard comm[16] thread name string.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1445784728-21732-4-git-send-email-jolsa@kernel.org
[ Renamed thread_map_data_event to thread_map_event_entry ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add new PERF_RECORD_SWITCH event</title>
<updated>2015-07-24T01:51:13+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2015-07-21T09:44:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0286039f777ec0b6684868c34f7b16f97a069d6e'/>
<id>0286039f777ec0b6684868c34f7b16f97a069d6e</id>
<content type='text'>
Support processing of PERF_RECORD_SWITCH events and
PERF_RECORD_SWITCH_CPU_WIDE events. There is a single
tools callback for them both so that the tool must
check the event type before using the extra members
in PERF_RECORD_SWITCH_CPU_WIDE.

There is still no way to select the events, though.
That is added in a subsequest patch.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Pawel Moll &lt;pawel.moll@arm.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1437471846-26995-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Support processing of PERF_RECORD_SWITCH events and
PERF_RECORD_SWITCH_CPU_WIDE events. There is a single
tools callback for them both so that the tool must
check the event type before using the extra members
in PERF_RECORD_SWITCH_CPU_WIDE.

There is still no way to select the events, though.
That is added in a subsequest patch.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Pawel Moll &lt;pawel.moll@arm.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1437471846-26995-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: handle PERF_RECORD_LOST_SAMPLES</title>
<updated>2015-06-07T14:09:06+00:00</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2015-05-10T19:13:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c4937a91ea56b546234b0608a413ebad90536d26'/>
<id>c4937a91ea56b546234b0608a413ebad90536d26</id>
<content type='text'>
This patch modifies the perf tool to handle the new RECORD type,
PERF_RECORD_LOST_SAMPLES.

The number of lost-sample events is stored in
.nr_events[PERF_RECORD_LOST_SAMPLES]. The exact number of samples
which the kernel dropped is stored in total_lost_samples.

When the percentage of dropped samples is greater than 5%, a warning
is printed.

Here are some examples:

Eg 1, Recording different frequently-occurring events is safe with the
      patch. Only a very low drop rate is associated with such actions.

$ perf record -e '{cycles:p,instructions:p}' -c 20003 --no-time ~/tchain ~/tchain

$ perf report -D | tail
          SAMPLE events:     120243
           MMAP2 events:          5
    LOST_SAMPLES events:         24
  FINISHED_ROUND events:         15
cycles:p stats:
           TOTAL events:      59348
          SAMPLE events:      59348
instructions:p stats:
           TOTAL events:      60895
          SAMPLE events:      60895

$ perf report --stdio --group
 # To display the perf.data header info, please use --header/--header-only options.
 #
 #
 # Total Lost Samples: 24
 #
 # Samples: 120K of event 'anon group { cycles:p, instructions:p }'
 # Event count (approx.): 24048600000
 #
 #         Overhead  Command      Shared Object     Symbol
 # ................  ...........  ................
 ..................................
 #
    99.74%  99.86%  tchain_edit  tchain_edit       [.] f3
     0.09%   0.02%  tchain_edit  tchain_edit       [.] f2
     0.04%   0.00%  tchain_edit  [kernel.vmlinux]  [k] ixgbe_read_reg

Eg 2, Recording the same thing multiple times can lead to high drop
      rate, but it is not a useful configuration.

$ perf record -e '{cycles:p,cycles:p}' -c 20003 --no-time ~/tchain
Warning: Processed 600592 samples and lost 99.73% samples!
[perf record: Woken up 148 times to write data]
[perf record: Captured and wrote 36.922 MB perf.data (1206322 samples)]
[perf record: Woken up 1 times to write data]
[perf record: Captured and wrote 0.121 MB perf.data (1629 samples)]

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: acme@infradead.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285195-14269-9-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch modifies the perf tool to handle the new RECORD type,
PERF_RECORD_LOST_SAMPLES.

The number of lost-sample events is stored in
.nr_events[PERF_RECORD_LOST_SAMPLES]. The exact number of samples
which the kernel dropped is stored in total_lost_samples.

When the percentage of dropped samples is greater than 5%, a warning
is printed.

Here are some examples:

Eg 1, Recording different frequently-occurring events is safe with the
      patch. Only a very low drop rate is associated with such actions.

$ perf record -e '{cycles:p,instructions:p}' -c 20003 --no-time ~/tchain ~/tchain

$ perf report -D | tail
          SAMPLE events:     120243
           MMAP2 events:          5
    LOST_SAMPLES events:         24
  FINISHED_ROUND events:         15
cycles:p stats:
           TOTAL events:      59348
          SAMPLE events:      59348
instructions:p stats:
           TOTAL events:      60895
          SAMPLE events:      60895

$ perf report --stdio --group
 # To display the perf.data header info, please use --header/--header-only options.
 #
 #
 # Total Lost Samples: 24
 #
 # Samples: 120K of event 'anon group { cycles:p, instructions:p }'
 # Event count (approx.): 24048600000
 #
 #         Overhead  Command      Shared Object     Symbol
 # ................  ...........  ................
 ..................................
 #
    99.74%  99.86%  tchain_edit  tchain_edit       [.] f3
     0.09%   0.02%  tchain_edit  tchain_edit       [.] f2
     0.04%   0.00%  tchain_edit  [kernel.vmlinux]  [k] ixgbe_read_reg

Eg 2, Recording the same thing multiple times can lead to high drop
      rate, but it is not a useful configuration.

$ perf record -e '{cycles:p,cycles:p}' -c 20003 --no-time ~/tchain
Warning: Processed 600592 samples and lost 99.73% samples!
[perf record: Woken up 148 times to write data]
[perf record: Captured and wrote 36.922 MB perf.data (1206322 samples)]
[perf record: Woken up 1 times to write data]
[perf record: Captured and wrote 0.121 MB perf.data (1629 samples)]

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: acme@infradead.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285195-14269-9-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add support for PERF_RECORD_ITRACE_START</title>
<updated>2015-05-05T21:12:58+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2015-04-30T14:37:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0ad21f6869222fd7fd7c63f02febea082e801fc2'/>
<id>0ad21f6869222fd7fd7c63f02febea082e801fc2</id>
<content type='text'>
Add support for the PERF_RECORD_ITRACE_START event type.  This event can
be used to determine the pid and tid that are running when Instruction
Tracing starts.  Generally that information would come from a
sched_switch event but, at the start, no sched_switch events may yet
have been recorded.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1430404667-10593-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for the PERF_RECORD_ITRACE_START event type.  This event can
be used to determine the pid and tid that are running when Instruction
Tracing starts.  Generally that information would come from a
sched_switch event but, at the start, no sched_switch events may yet
have been recorded.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1430404667-10593-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
